KR20060017713A - Mems switch to be moved electromagnetic force and manufacture method thereof - Google Patents

Abstract

The present invention provides a high resistance silicon substrate; A fixed core part formed to have both core parts and a bottom core part of the high resistance silicon substrate; A coil embedded in a spiral winding at least one core part of both core parts of the fixed core; A signal connection terminal formed separately from each other at a distal end of the high resistance silicon substrate; It provides an electromagnetic force-driven MEMS switch and a manufacturing method comprising a movable core which is movable on the fixed core to connect the signal connection terminal. The present invention implements a self-driven MEMS switch that can be used at a low voltage to secure high efficiency, low loss, and broadband characteristics, which are disadvantages of the conventional FET switch, thereby enabling a switching array that can be used in next-generation mobile terminals and expensive semiconductor measurement equipment. It is applicable to and is expected to get great business effect. Compared with other conventional magnetically driven switches, it has a good performance by using a structure that is significantly improved in heat dissipation and power consumption, and can be used at a high frequency and is compatible with other processes, such as a filter bank of a wireless communication device. Can be used as In addition, since it is easy to integrate on a silicon substrate, it is possible to fully integrate with a CMOS circuit, and thus it has an advantage that it can be widely applied to various fields.

Description

MEMS switch of electromagnetic force driving and its manufacturing method {MEMS SWITCH TO BE MOVED ELECTROMAGNETIC FORCE AND MANUFACTURE METHOD THEREOF}

1 to 3 show an electromagnetic force driving MEMS switch according to an embodiment of the present invention,

1 is a plan view of an electromagnetic force driven MEMS switch.

2 is a longitudinal sectional view of an electromagnetic force driven MEMS switch.

3 is an explanatory view of the operation of the electromagnetic force driven MEMS switch.

Figure 4 is a process chart for explaining the electromagnetic force driven MEMS switch manufacturing method.

5 and 6 are views showing an electromagnetic force driven MEMS switch according to another embodiment of the present invention.

7 and 8 show an electromagnetic force driving MEMS switch according to another embodiment of the present invention.

9 and 10 show an electromagnetic force driving MEMS switch according to another embodiment of the present invention.

11 and 12 show an electromagnetic force driven MEMS switch according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: high resistance silicon substrate

110; 111, 112, 113, 115: fixed core

110a, 110b: Both core parts

110c: bottom core portion

120; 121,122,123,125: coil

130; 131,132,133,135: movable core

140; 141,142: Signal connection terminal

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch widely used for shielding signals in mobile and telecommunication circuits and semiconductor test equipment. In particular, an electromagnetic force driver having a magnetic core and a coil consisting of a fixed core and a movable core is formed on a high resistance silicon substrate. The present invention relates to a MEMS switch for electromagnetic force driving and a method of manufacturing the same, which are provided at a low voltage by forming a pair of signal connection terminals disconnected at an intermediate portion or one side of the electromagnetic force driver.

In general, the switch is a representative component widely used in most electronic products, ranging from general home appliances to recent wireless mobile communication devices. As the additional functions of various electronic products are added, the switch has a large number of parts even in a single product. This is used.

Among them, FET (Field Effect Transistor) is a switch type of semiconductor type and mainstream with small size and low price. However, the recent emergence of MEMS technology can control the opening and closing of circuit through mechanical driving rather than switching by electric field effect. The MEMS switch has been started to be implemented in the form of a relay, which is generally classified according to the method of generating driving force because mechanical driving occurs directly.

 First, there is the electrostatic drive method which is currently being researched and developed the most. The electrostatic driving method has a basic concept of shielding a circuit by mutual attraction generated by applying voltages of the anode and the cathode to the structure that can be deformed in the elastic region, respectively. The electrostatic drive method has the advantages of low power consumption and simple structure and easy implementation. Since the driving force is generated by the applied voltage difference, several tens of volts or more are required for driving with reliability. Therefore, it is not easy to apply to portable mobile devices such as mobile phones, which require the use of low voltage.

Self-driven MEMS switches have the advantages of low driving voltage, large driving force and displacement, but they are difficult to manufacture due to their complicated structure and high power consumption, which has not been studied much until now. R & D is being actively conducted since these can be improved.

As mentioned above, the self-driven MEMS switch has a disadvantage in that it is difficult to implement structurally, and thus many studies have not been conducted until now.

Therefore, various improvements have to be made to alleviate these shortcomings. First, the area must be minimized and the process steps reduced. Secondly, the maximum cross-sectional area of the coil should be secured and the sheet resistance should be minimized to secure the maximum amount of current and driving force. Finally, thermal dissipation should be maximized by using insulators with the highest possible thermal conductivity.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems and defects. The present invention provides an electromagnetic force driver having a magnetic core and a coil consisting of a fixed core and a movable core on a high resistance silicon substrate, and an intermediate portion of the electromagnetic force driver or An object of the present invention is to provide an electromagnetic force-driven MEMS switch and a method of manufacturing the same, by forming a pair of signal connection terminals disconnected at one side thereof to enable use at a low voltage.

MEMS switch of the electromagnetic force drive according to the present invention in order to achieve the above object is a fixed core (core) consisting of a lower horizontal portion (bottom magnetic core) and its vertical side (side magnetic core) and a coil ( coils, signal lines, and movable cores of movable upper magnetic plates that move up and down by hinges to connect the signal connection terminals, which are high resistance silicon substrates. Characterized in that the integrated configuration.

That is, a high resistance silicon substrate, a fixed core formed to have both core parts and a bottom core part on the high resistance silicon substrate, a coil formed around the central vertical portion of the fixed core on the high resistance silicon substrate, and the high resistance silicon And a cantilever movable core formed at one end of the substrate, and a signal connection terminal formed separately from each other at the other end of the high resistance silicon substrate and connected by the movable core.

The present invention uses a high-resistance silicon wafer to form a conventional coil portion into a wafer, that is, to form a recessed shape in which a groove is inserted into a wafer and a coil is inserted into a conventional polymer / metal type multilayer process. It is easier to implement a three-dimensional structure that eliminates instability and non-uniformity due to high inductance.Since high-resistance silicon acts as an insulator, it is possible to implement a high aspect ratio conductor structure, which reduces electric resistance and allows more current to pass. Can be obtained and power consumption can be reduced. In addition, when using a conventional polymer-based insulator, there was a disadvantage that the heat dissipation is very difficult due to the high thermal resistance of the polymer itself, but the present invention using the high-resistance ?? icon brings an improvement in performance to improve such a problem. The use of high-resistance silicon minimizes the loss from the substrate in the high frequency band.

The present invention is an electromagnetic force-driven MEMS switch for application to next generation mobile terminals and reconfigurable systems, and a method of manufacturing the same, unlike conventional semiconductor-type switches, low loss using ultra micromechanical system processing technology. The high isolation, high isolation, and broadband characteristics make it widely applicable to the next generation of mobile and wireless communication systems.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail as follows.

1 to 3 show an electromagnetic force driving MEMS switch according to an embodiment of the present invention, Figure 1 is a plan view of the electromagnetic force driving MEMS switch, Figure 2 is a longitudinal cross-sectional view of the electromagnetic force driving MEMS switch, 3 is an explanatory view of the operation of the electromagnetic force driven MEMS switch.

As shown, the MEMS switch of the electromagnetic force driving according to an embodiment of the present invention is a high-resistance silicon substrate (wafer) 100, and the core portion (110a), (110b) on both sides of the high-resistance silicon substrate (100) And fixed core (110; 111) is formed buried so that the bottom core portion (110c) is provided; A coil (120; 121) formed in an oblong spiral winding around at least one core (110a) of both core parts (110a) and (110b) of the fixed core (110; 111); Signal connection terminals 140; 141 and 142 separated from each other at the front end of the high resistance silicon substrate 100; And a movable core (130; 134) formed on the fixed core (110; 111) to be movable to connect the signal connection terminals (140; 141, 142).

The coils 120 and 121 are formed around the front core part 110a of the fixed cores 110 and 111, and the signal connection terminals 140, 141 and 142 are formed at the front outer part of the coils 120 and 121, respectively. It is formed, the movable core (130; 131) is connected to the rear end of the fixed core (110; 111) of the rear core portion (110b) of the fixed portion (131b), the connection of the front end of the movable core (130; 131) The stage 131a is configured to connect the signal connection terminals 140; 141 and 142.

Figure 4 is a process chart for explaining the electromagnetic force driven MEMS switch manufacturing method according to the present invention, the manufacturing process of the electromagnetic force driven MEMS switch device according to the present invention is shown in the process diagram of FIG.

First, as shown in FIGS. 4A and 4B, the high resistance silicon substrate 100 is etched with a straight wall to form coils 120 and 121. On the other hand, the implementation of the structure by the conventional polymer-type mold had a limitation in the high aspect ratio, but the mold through the silicon etching can be realized up to a high aspect ratio of 40: 1 as known, and now it is required to develop the plating technology. have. And to reduce the size of the device and to reduce the electrical resistance to reduce the line width of the coil (120; 121) to form a deep trench (groove) to form a coil through copper electroplating, such as good electrical conductivity.

Subsequently, in the process of FIG. 4C, the fixed cores 110 and 111 are formed on the high-resistance silicon substrate 100 and relatively high, such as nickel or a nickel alloy, to induce a magnetic current at a low voltage as much as possible to obtain a high magnetic flux density. Materials with permeability can also be implemented through the plating process.

The fixed core part 110a, the outer end vertical part 110b, and the lower horizontal part 110c of the coils 120 and 121 are all formed at this stage, or previously formed with the lower horizontal part 110c. One side fixed core portion 110a and the outer end vertical portion 110b may be formed at this stage.

Subsequently, as shown in FIG. 4D, the signal connection terminals 140; 141 and 142 are formed on the right end of the high resistance silicon substrate 100 in a form of being separated from each other.

4E and 4F, the movable cores 130 and 131 of the cantilever beam are formed to have one end connected to the left end of the high resistance silicon substrate 100.

Formation of the structure is formed by repeating the formation of a pattern using a photosensitive photosensitive process, the formation of a mold using a dry etching, the formation of a seed layer for electroplating through sputtering, and finally the electroplating process. The process of Figures 4d, e, f proceeds to the formation of a mold using photoresist and photosensitive polyimide, commonly referred to as surface micromachining, to the electroplating and removal of the sacrificial layer.

In the MEMS switch of the electromagnetic force driving according to the present invention, when a current flows in the coil 120; 121, magnetic flux is generated at one side of the fixed core 110a of the fixed core 110; At the center portion of the cantilever, the movable cores 130 and 131 of the cantilever move downward, and two signal connection terminals 140, 141 and 142 are connected.

In addition, when the applied current is cut off, the movable cores 130 and 131 are double-acted upward, and the signal connection terminals 140 and 141 and 142 are disconnected. On / off switching is performed by the movement of the movable cores 130 and 131. Use principles that work.

5 and 6 illustrate an electromagnetic force driving MEMS switch according to another embodiment of the present invention, in which the movable cores 130 and 134 have a wider width than those of the embodiments shown in FIGS. 1 to 3. Has a tapered shape that is gradually narrower in width as the front portion goes to the connecting end (134a), and other configurations and actions are the same as in one embodiment.

7 and 8 are diagrams illustrating an electromagnetic force driving MEMS switch according to another embodiment of the present invention. As shown therein, both core parts 110a and 110b and a bottom core part of the high resistance silicon substrate 100 are shown. Coils 120 and 122 are formed around both core portions 110a and 110b of the fixed cores 110 and 112 formed to have the 110c, respectively, and a signal is formed at the front outer portion of the coils 120 and 122, respectively. Connection terminals 140 and 141 and 142 are formed, and the fixed end 132b of the rear end of the movable core 130 and 132 is connected to the rear core portion 110b of the fixed core 110 and 112, thereby allowing the movable core 130 to be connected. 132) The connecting end 132a at the tip is configured to connect the signal connecting terminals 140; 141 and 142.

7 and 8 have a fixed core (110; 112) and two coils (120; 122) provided with two vertical magnetic fixing cores, and cantilever, ie, movable, magnetic thin film. The fixed ends 132b of the cores 130 and 132 are connected to the outer vertical self-fixing core portions of the fixed cores 110 and 111 so that the connection ends 132a of the movable cores 130 and 131 are signal connection terminals 140 and 141 and 142. ) Is connected.

9 and 10 are diagrams illustrating an electromagnetic force driving MEMS switch according to another embodiment of the present invention, wherein both core parts 110a and 110b and the bottom core part 110c are formed on the high resistance silicon substrate 100. A pair of coils 120 and 123 are formed around both of the core parts 110a and 110b of the fixed cores 110 and 113 formed to be provided, and both ends of the movable cores 130 and 133 are formed at the high end. Resilient hinge (133b) is connected to the resistive silicon substrate 100, the signal connection terminals 140; 141, 142 are formed in the middle of both coils (120; 123), the movable core (130; 133) It is comprised so that it may be connected by the intermediate | middle connection part 133a of ().

9 and 10 illustrate two two core parts 110a and 110b having the signal connection terminals 140 and 141 and 142 provided in the fixed cores 110 and 113, and two coils 120 and 123. The movable cores 130 and 133 of the bridge of the magnetic thin film, which are arranged in the center of the electromagnetic force driver having the center of the electromagnetic force driver, are connected to the elastic hinge 133b having a low spring constant at four ends. The intermediate connection part 133a of the movable cores 130 and 133 connects the signal connection terminals 140 and 141 and 142.

11 and 12 are diagrams illustrating an electromagnetic force driving MEMS switch according to another embodiment of the present invention, wherein both core parts 110a and 110b and the bottom core part 110c are formed on the high resistance silicon substrate 100. Coils 120 and 125 are formed around one side core portion 110a of the fixed cores 110 and 115, and both ends of the movable cores 130 and 135 are formed on the high resistance silicon substrate 100. Is connected to the elastic hinge (135b) to be extensible, and the signal connection terminals (140; 141, 142) are formed in the front outer portion of the coil (120; 125) to the connecting end (135a) in front of the movable core (130; 135) It is configured to be connected by).

11 and 12 illustrate that the disconnected signal connection terminals 140 and 141 and 142 have fixed cores 110 and 115 having both core parts 110a and 110b and one coil 120 and 125, respectively. The movable core (130; 135) is connected to an elastic hinge (135b) having a low spring constant at one end of the movable core (130; 135) of the cantilever moving as a structure located on the side of the coil (120; 125) of the electromagnetic force driver. Is elastically rotated by the elastic hinge 135b so that the tip connecting end 135a of the movable core 130; 135 connects the signal connecting terminals 140; 141 and 142.

As described above, the present invention implements a self-driven MEMS switch that can be used at a low voltage of 3 V or less, thereby securing high efficiency, low loss, and broadband characteristics, which are disadvantages of the conventional FET switch, thereby enabling next-generation mobile terminals and expensive semiconductor measurement equipment. It can be applied to switching arrays that can be used in the system, and it is expected to have a great business effect. Compared with other conventional magnetically driven switches, it has a good performance by using a structure that is significantly improved in heat dissipation and power consumption, and can be used at a high frequency and is compatible with other processes, such as a filter bank of a wireless communication device. Can be used as In addition, since it is easy to integrate on a silicon substrate, it is possible to fully integrate with a CMOS circuit, and thus it has an advantage that it can be widely applied to various fields.

Claims (7)

A high resistance silicon substrate; A fixed core part formed to have both core parts and a bottom core part of the high resistance silicon substrate; A coil embedded in a spiral winding at least one core part of both core parts of the fixed core; A signal connection terminal formed separately from each other at a distal end of the high resistance silicon substrate; And a movable core movably formed on the fixed core to connect the signal connection terminal. The method of claim 1, wherein the coil is formed around the front core of the fixed core, the signal connection terminal is formed at the front outer side of the coil, and the movable core is formed at the rear core of the fixed core. And a connection end of the movable core end connected to the government unit to connect the signal connection terminal. The method of claim 1, wherein coils are formed around both core portions of the fixed core, and the signal connection terminals are formed at the front outer side of the coil, and the fixed ends of the rear end of the movable core are formed at the rear core of the fixed core. And a connection end of the front end of the movable core is configured to connect the signal connection terminal. The method of claim 1, wherein a pair of coils are formed around both core portions of the fixed core, and both ends of the front and rear portions of the movable core are flexibly connected to the high resistance silicon substrate by an elastic hinge. And a signal connection terminal formed in an intermediate portion of both coils, and configured to be connected by an intermediate connection portion of the movable core. The method of claim 1, wherein a coil is formed around one core of the fixed core, and both ends of the rear portion of the movable core are flexibly connected to the high resistance silicon substrate by an elastic hinge, and the signal connection terminal is And an electromagnetic force driving MEMS switch formed at a front outer side of the coil and configured to be connected by a connection end in front of the movable core. Etching the high resistance silicon substrate with a straight wall and embedding a coil; Etching the high resistance silicon substrate and embedding a fixed core having both core parts and a bottom core part; Separating signal connection terminals from each other on the high resistance silicon substrate; Electromagnetic force driven MEMS switch manufacturing method comprising the step of performing a movable core on top of the movable core of the high resistance silicon substrate. The method of claim 6, wherein the structure is formed by repeating the electroplating process by forming a pattern using a photosensitive process and forming a mold using dry etching, forming a seed layer for electroplating through sputtering, and finally performing the electroplating process. Forming process is a step of forming a mold using a photoresist and photosensitive polyimide, electroplating and removing the sacrificial layer, characterized in that the electromagnetic force driven MEMS switch manufacturing method.

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